The present invention relates to a device for damping vibrations of a frame that is guided on guiderails by means of guide elements and carries an elevator car body. Vibrations that occur perpendicular to the direction of travel are measured by acceleration sensors fastened to the frame, and are used to control at least one actuator arranged between the frame and the guide elements, the actuator acting simultaneously with, and in the opposite direction to, the vibrations.
The European patent specification EP 0 731 051 B1 shows a method and a device by which vibrations of an elevator car, which is guided on rails, occurring perpendicular to the direction of travel are reduced by means of a feedback control acting in the high-frequency range, so that the vibrations are not perceptible in the car. For the purpose of capturing the measurement values, inertia sensors are fastened to the car frame. In the event of a one-sided inclination of the car relative to the rails, a position controller acting in the low-frequency range guides the car automatically back into a central position so that an adequate damping distance is always available. Position sensors deliver the measurement values to the position controller. Actuators are provided with linear motors to adjust the position of the rollers. On each roller guide, a first linear motor controls two side rollers, and a second linear motor controls the middle roller. The cost for such equipment for executing the method is low, since the two control loops are combined into a common feedback control, and act on one actuator.
A disadvantage of this known device is that the elevator itself must have a rigid structure in order that the ride comfort is assured by the vibration control.